Design Fabrication And Testing Of Silicon Resonators For Opto Acoustic Parametric Amplifiers

[Truncated abstract] The development of gravitational-wave detectors has involved pushing the frontiers oftechnology in many areas. One of these efforts, km-long optical cavities with high optical power, led to the realisation that 3-mode opto-acoustic interactions could occur in these systems [1, 2]. In researching this problem, Zhao et al. [3] recognised that the concepts could be utilised to make new ultra-sensitive opto-acoustic devices.The thesis reports the development of acoustic resonators that would form the heart of a 3-mode opto-acoustic parametric amplifier (OAPA), and presents the design of such an amplifier and predictions of its performance.Finite element modelling (FEM) is used to choose an appropriate design for an acoustic resonator to be incorporated in a novel OAPA device. Acoustic resonator prototypes range from single-paddle designs [3] to 3-paddle designs inspired by Davis et al. [4]. Predictions of optical coating losses are presented as a function of size and location of coatings on the 3-paddle resonator design. Four models are identified as showing the most promise.Various resonator fabrication techniques and experimental setups to test resonators are discussed. Nodes and antinodes from the acoustic wave of a torsional mode (the mode of interest) in the frame are modelled with FEM to determine the optimal suspension locations of a 3-point contact setup.

Reference oscillators are ubiquitous elements used in almost every electronics system today. The need for miniaturized, batch manufacturable oscillators as chipscale timing references arises from the quest to replace the well-established, high performance yet expensive quartz-based oscillators, without compromising performance. The electrical specifications of an oscillator depend on the application it serves, which has resulted in a variety of different mainstream oscillator technologies. Consumer RF applications can broadly be classified mechanical oscillators and electrical oscillators. In mechanical oscillators, the frequency selective element is a mechanical resonator, and typically quartz is the material of choice for high-end applications. For less demanding and cost-sensitive applications, micro-electromechanical (MEMS) resonators, being CMOS compatible and high quality factor resonators, offer a unique set of parameters well-suited for oscillator design. Electrostatic capacitive transduced silicon resonators and piezoelectric transduced thin film bulk acoustic resonators (FBARs) are commercially available for MHz range and GHz range applications respectively. Scaling MEMS oscillators to higher frequencies presents challenges in terms of reduced transduction efficiencies and material limitations on quality factors. Opto-mechanical transduction offers higher sensitivity and opens up possibilities to interrogate high frequency mechanical resonances hitherto inaccessible. The focus of this thesis is to leverage opto-mechanical transduction to design high frequency high performance MEMS oscillators and exploring various designs and fabrication techniques to realize these devices. This disertation explores two classes of oscillators, namely the opto-mechanical and opto-acoustic oscillators. The former oscillator type exploits parametric amplification and does not require external electrical feedback to sustain oscillations, thus doing away with a dominant noise source. To eliminate coupling environmental noise to the oscillation signal, the opto-mechanical resonator was fabricated on a silicon nitride chip with waveguides and grating couplers integrated on to the same chip. The device was used to demonstrate self-sustained mechanical oscillations at 41MHz with phase noise -91dBc/Hz at 1kHz offset from carrier. The integrated design results in immunity of the oscillation signal from environmental flicker noise. Designing low phase noise opto-mechanical oscillators for GHz range frequencies is very challenging, the limitations being mainly imposed by the efficiency of the optical drive scheme. A design worth exploring to overcome this limitation is the acousto-optic modulator designed and developed in the OxideMEMS lab, which marries the highly sensitive optical sense scheme with electrostatic capacitive transduced drive scheme. Operating the modulator in a feedback loop as an opto-acoustic oscillator has been realized by using the device as an intensity modulator. However the two-coupled opto-mechanical resonator design cannot be successfully scaled to design an oscillator at frequencies beyond GHz. An alternative efficient transduction scheme of interest for GHz range MEMS resonators is partial air gap capacitive transduction. Exploiting partial air-gap transduction using alumina in addition to designing an array of resonators employing a micromechanical displacement amplifier, an opto-acoustic oscillator employing a higher order radial mode at 2.1GHz was demonstrated. The oscillator has RF output power of +18dBm and phase noise -80dBc/Hz at 10kHz offset from carrier. The inherent non-linearity of the opto-mechanical modulation based sensing generates oscilllation harmonics all the way up to 16.4GHz with greater than -45dBm signal power. A detailed phase noise model for such oscillators was derived and insights derived from the model were followed to identify appropriate photo-detectors to lower the far-from-carrier phase noise by 15dB. Fabrication techniques developed along the way were also used to design other interesting opto-mechanical devices for electromechanical detection of optical modulation and to study acousto-optic frequency modulation. In summary, the overall focus of this work is to bring together MEMS and photonics techniques and devices in ways that address long-standing needs in both communities.

The operational amplifier ("op amp") is the most versatile and widely used type of analog IC, used in audio and voltage amplifiers, signal conditioners, signal converters, oscillators, and analog computing systems. Almost every electronic device uses at least one op amp. This book is Texas Instruments' complete professional-level tutorial and reference to operational amplifier theory and applications. Among the topics covered are basic op amp physics (including reviews of current and voltage division, Thevenin's theorem, and transistor models), idealized op amp operation and configuration, feedback theory and methods, single and dual supply operation, understanding op amp parameters, minimizing noise in op amp circuits, and practical applications such as instrumentation amplifiers, signal conditioning, oscillators, active filters, load and level conversions, and analog computing. There is also extensive coverage of circuit construction techniques, including circuit board design, grounding, input and output isolation, using decoupling capacitors, and frequency characteristics of passive components. The material in this book is applicable to all op amp ICs from all manufacturers, not just TI. Unlike textbook treatments of op amp theory that tend to focus on idealized op amp models and configuration, this title uses idealized models only when necessary to explain op amp theory. The bulk of this book is on real-world op amps and their applications; considerations such as thermal effects, circuit noise, circuit buffering, selection of appropriate op amps for a given application, and unexpected effects in passive components are all discussed in detail. *Published in conjunction with Texas Instruments *A single volume, professional-level guide to op amp theory and applications *Covers circuit board layout techniques for manufacturing op amp circuits.

The new edition of the leading resource on designing digital frequency synthesizers from microwave and wireless applications, fully updated to reflect the most modern integrated circuits and semiconductors Microwave and Wireless Synthesizers: Theory and Design, Second Edition, remains the standard text on the subject by providing complete and up-to-date coverage of both practical and theoretical aspects of modern frequency synthesizers and their components. Featuring contributions from leading experts in the field, this classic volume describes loop fundamentals, noise and spurious responses, special loops, loop components, multiloop synthesizers, and more. Practical synthesizer examples illustrate the design of a high-performance hybrid synthesizer and performance measurement techniques—offering readers clear instruction on the various design steps and design rules. The second edition includes extensively revised content throughout, including a modern approach to dealing with the noise and spurious response of loops and updated material on digital signal processing and architectures. Reflecting today's technology, new practical and validated examples cover a combination of analog and digital synthesizers and hybrid systems. Enhanced and expanded chapters discuss implementations of direct digital synthesis (DDS) architectures, the voltage-controlled oscillator (VCO), crystal and other high-Q based oscillators, arbitrary waveform generation, vector signal generation, and other current tools and techniques. Now requiring no additional literature to be useful, this comprehensive, one-stop resource: Provides a fully reviewed, updated, and enhanced presentation of microwave and wireless synthesizers Presents a clear mathematical method for designing oscillators for best noise performance at both RF and microwave frequencies Contains new illustrations, figures, diagrams, and examples Includes extensive appendices to aid in calculating phase noise in free-running oscillators, designing VHF and UHF oscillators with CAD software, using state-of-the-art synthesizer chips, and generating millimeter wave frequencies using the delay line principle Containing numerous designs of proven circuits and more than 500 relevant citations from scientific journal and papers, Microwave and Wireless Synthesizers: Theory and Design, Second Edition, is a must-have reference for engineers working in the field of radio communication, and the perfect textbook for advanced electrical engineering students.

This book introduces piezoelectric microelectromechanical (pMEMS) resonators to a broad audience by reviewing design techniques including use of finite element modeling, testing and qualification of resonators, and fabrication and large scale manufacturing techniques to help inspire future research and entrepreneurial activities in pMEMS. The authors discuss the most exciting developments in the area of materials and devices for the making of piezoelectric MEMS resonators, and offer direct examples of the technical challenges that need to be overcome in order to commercialize these types of devices. Some of the topics covered include: Widely-used piezoelectric materials, as well as materials in which there is emerging interest Principle of operation and design approaches for the making of flexural, contour-mode, thickness-mode, and shear-mode piezoelectric resonators, and examples of practical implementation of these devices Large scale manufacturing approaches, with a focus on the practical aspects associated with testing and qualification Examples of commercialization paths for piezoelectric MEMS resonators in the timing and the filter markets ...and more! The authors present industry and academic perspectives, making this book ideal for engineers, graduate students, and researchers.

Nonlinear photonics is the name given to the use of nonlinear optical devices for the generation, communication, processing, or analysis of information. This book is a progress report on research into practical applications of such devices. At present, modulation, switching, routing, decision-making, and detection in photonic systems are all done with electronics and linear optoelectronic devices. However, this may soon change, as nonlinear optical devices, e.g. picosecond samplers and switches, begin to complement optoelectonic devices. The authors succinctly summarize past accomplishments in this field and point to hopes for the future, making this an ideal book for newcomers or seasoned researchers wanting to design and perfect nonlinear optical devices and to identify applications in photonic systems.